In the inoculation of molten metal, for example cast iron including ductile iron, compacted graphite iron, malleable iron, and others, preferably gray iron, inoculation materials are sometimes introduced into the molten metal by an encompassing conduit. By providing a conduit having the inoculant therein, the resultant inoculating article is generally in wire form and can conveniently be controllably fed by feeding apparatus into molten metal simultaneously being poured into a mold, as is known in the art.
The heretofore utilized inoculating articles functioned satisfactory in some applications, but, in other situations, performed with less than desirable efficiency. This less than desirable efficiency generally resulted from maximum obtainable feed rates, nonuniformity of inoculant dispersion, melting temperatures of the components of the articles, and other factors.
One of the greatest problems encountered was in inoculating molten metal with preselected inoculating materials while maintaining the temperature of the molten metal at a preselected low value. Owing to the current shortages of energy in the world, it is desirable to maintain the molten metal at a desirably low temperature in order to avoid the waste of energy. At these desirable low temperatures of the molten metal, the specific inoculant desired to be utilized and the conduit sometimes would not melt.
The present invention is directed to overcoming one or more of the problems as set forth above.
According to the present invention, an inoculating article has a steel conduit having inoculating material positioned within the conduit. The inoculating material is ferro-silicon having a silicon content greater than about 75% by weight and the inoculating material is compacted within the conduit.